The number of major crimes reported in Washington increased by 8 percent during the second three months of this year as compared to the same period last year, District police officials said yesterday.

In announcing the new statistics, Police Chief Burtell M. Jefferson noted that the rate of increase was well below that of the first quarter of the year, but declared that "no crime increase is acceptable. I'm not particularly pleased with the figures."

Jefferson said the second quarter crime figures show the rate of increase diminishing since the first three months of this year, when crime rose 23 percent.

"We are hoping that this downswing is a trend that will continue," Jefferson said.

Crime actually declined during July and August and "it looks encouraging," he said.

"Naturally, I'm pleased that the number of reported incidents are down from last quarter," said Mayor Marion Barry. "We plan to work hard to get them down even further."

Crime for the 12-month period ending in June, however, increased 12 percent, with burglaries -- at 17 percent -- showing the sharpest rise.

For April, May and June, crimes against persons -- homicide, rape, robbery and assault -- increased 6 percent. Crimes against property -- burglary, larceny, auto theft -- jumped 9 percent.

"The whole economic situation has a bearing on the crime trend," Jefferson said. He blamed unemployment and inflation for the increase.

He also attributed the rise in crime to increased narcotic use in the city -- especially jumps in burglaries and larcencies.

Burglaries totaled 3,065, up 4 percent; larcenies totaled 7,054, up 12 percent, and auto theft totaled 818, up 3 percent.

In crimes against persons, the totals are 50 homicides, up 2 percent; 119 rapes, down 23 percent; 1,484 robberies, up 11 percent and 686 aggravated assaults, up 3 percent.

Offenses in the second three months of the year totaled 13,276.

Geographically, the 3rd Police District, an area north of downtown that includes the center of the city's prostitution and drug trade, led in crime with a 16 percent increase.

The 1st District, which covers downtown and parts of Capitol Hill, and the 2nd District, west of Rock Creek Park, each showed a 12 percent increase. almost entirely in property crimes. The 6th District, which includes Far Northeast beyond the Anacostia River, and the 4th District, east of Rock Creek Park, showed 2 and 3 percent increases, respectively.

The 5th District, which includes Northeast and parts of Capitol Hill, had the lowest increase -- slightly less than 1 percent.

Jefferson said he discussed the increase in crime with his commanders at a three-day seminar held last week in Harpers Ferry. He said he emphasized that "the maximum effort" should be used to reverse the increase.

A police spokesman said the crime prevention van, unveiled by police earlier this week, will be used in the districts to educate citizens on how to protect themselves against crime.